This invention concerns a combined dust cap and position indicating device, particularly but not exclusively for use upon vehicle wheel nuts.
The applicants"" earlier patent, GB 2 242 720, discloses a simple device enabling visual inspection to be carried out so as to indicate whether or not a wheel nut has become loose or is starting to become loose.
In general terms, the earlier invention provided a safety device for indicating relative rotational displacement between a fixed first member and a second member which is rotatably engaged with the first member, the device comprising a body having a bore formed with equispaced grooves enabling the device to be releasably secured to the second member in one position of a plurality of positions, and having indicating means, such as a pointer, to indicate the position of the device relative to a reference.
As mentioned, such a device is particularly useful for indicating whether or not a wheel nut has become loose, in which respect the first member comprises a threaded stud on an axle hub, the second member comprises a wheel nut, and the reference comprises a mark on a wheel rim adjacent a respective stud hole.
The present invention is a useful development of the previous safety device, as defined above, and is characterised in that in such a device the bore is closed at one end so that the body additionally serves as a dust cap for conjoined first and second members.
The indicating means can comprise a pointer and the body and the pointer can be formed either integrally or as separate components.
The bore in the body can be closed by a removable cap and the pointer can be formed either integrally with the cap or the body or as a separate component which is securable to the body.
The present invention further comprises a vehicle wheel and hub assembly comprising studs on the hub and associated nuts securing the vehicle wheel to the hub, a safety device as defined in the preceding paragraphs being arranged on each nut when tightened, so that each device points to a reference.